Two in five U.S. households rely solely on a cellphone, CDC researchers say

128 million Americans were 'wireless only' by the end of 2013, government data show

Americans without land lines are more likely to smoke, drink and go without health insurance, survey finds

The number of Americans living in households without traditional land-line telephones continues to grow, according to new data from the Centers for Disease Control and Prevention.

In the second half of 2013, 41% of U.S. households relied solely on a wireless phone, researchers from the CDC’s National Center for Health Statistics reported Tuesday. That’s up from 38.2% in the second half of 2012, 34% in the second half of 2011 and 29.7% in the second half of 2010.

These wireless-only households included 93 million adults and nearly 35 million children, according to the study. That works out to 39.1% of American adults and 47.1% of American kids as of the second half of 2013.

Millions more Americans may be set to join them. The CDC report classified another 16.1% of U.S. households as being “wireless-mostly.” That means that although they have a land line, “all or almost all” of their calls are received on a wireless phone.

The researchers identified five groups of Americans in which the majority had dropped their land lines. Topping that list were adults who lived with unrelated adult roommates — 76.1% of them relied solely on a wireless phone. Next up were adults between 25 and 29, a group in which 65.7% were wireless-only. They were followed closely by adults who live in rental homes — 61.7% had only a wireless phone, according to the report.

Among adults living in poverty, 56.2% had a wireless phone but no land line, the researchers found. That compares with 46.1% of adults who were “near poverty” and 36.6% of adults who had a “higher income.”

Finally, 53.1% of Latino adults were wireless-only, the only racial or ethnic group to cross the 50% threshold. In comparison, 42.7% of blacks, 38.1% of Asians and 35.1% of whites had also ditched their land lines, according to the report.

Midwesterners were more likely than Americans from any other part of the country to be classified as wireless-only, with 43.7% earning that designation. Americans in the South and West were close behind, with 41.9% and 41.2%, respectively, relying solely on their wireless phones. By comparison, only 24.9% of Northeasterners had cut the cord to their land line, the researchers reported.

Men held the edge over women when it came to living in wireless households, by a slim margin of 40.4% to 37.9%.

The data in the report were collected as part of a large ongoing study called the National Health Interview Survey. In 2003 interviewers began asking subjects whether they had a wireless phone in addition to — or instead of — a land line.

It turns out that there are some noticeable health differences between Americans who are wireless-only and those who are not. Wireless-only adults were more likely to be smokers and drinkers than adults with a land line, the researchers found. For example, 29% of wireless-only adults told interviewers that they had consumed at least five alcoholic drinks in a single day at least once in the previous year, compared with 17.2% of adults with a land line.

Adults in wireless-only households were also more likely to go without health insurance in the second half of 2013 (25.2%) than their tethered counterparts (14.7%). They also had greater odds of experiencing “financial barriers to obtaining needed healthcare” and to be lacking “a usual place to go for medical care.”

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Were you planning on running this morning, but wasted too much time reading Twitter messages on your iPhone? When you do make it to the gym, do people give you the evil eye because you sit on a weight machine and text with a friend?

The next time you’re tempted to make a phone call while you’re behind the wheel, remember this: Dialing while driving increases the risk of a crash or near-crash more than any other sort of distraction.